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United States Patent |
5,138,859
|
Winkens
|
August 18, 1992
|
Method and apparatus for smooth-rolling and deep-rolling multi-stroke
crankshafts
Abstract
A method and apparatus for smooth-rolling and deep-rolling the journal pins
of multi-crank crankshafts divides the crank pins into two groups, each
including alternating crank pins, since the space between neighboring
crank pins is insufficient for simultaneously rolling all of the pins
including the main bearing pins in one operation. Each group of crank pins
is then rolled separately in succession, whereby one group includes the
main bearing pins. Thus, a crankshaft, including any number of closely
spaced crank pins, can be completely machined in two rolling operations.
In order to carry out this method a rolling apparatus includes crank pin
rolling devices for each of the pins of one group. The rolling devices are
axially slideably adjustable in unison between two determinable positions
in which they may be fixed or locked after adjustment. The crank pin
rolling devices are spaced from one another with a sufficient spacing in
the axial sliding direction so that at least one crank pin can pass
between two adjacent crank pin rolling devices.
Inventors:
|
Winkens; Rudolf (Erkelenz-Gerderath, DE)
|
Assignee:
|
Firma Wilhelm Hegenscheidt Gesellschaft mbH (Erkelenz, DE)
|
Appl. No.:
|
691388 |
Filed:
|
April 25, 1991 |
Foreign Application Priority Data
| Jun 15, 1990[EP] | 90111303.5 |
Current U.S. Class: |
72/110 |
Intern'l Class: |
B21K 001/08 |
Field of Search: |
72/107,110
|
References Cited
U.S. Patent Documents
4290238 | Sep., 1981 | Judge, Jr.
| |
4485537 | Dec., 1984 | Berstein et al. | 72/107.
|
Foreign Patent Documents |
0167659 | Jan., 1986 | EP.
| |
Primary Examiner: Larson; Lowell A.
Attorney, Agent or Firm: Fasse; W. G.
Claims
What I claim is:
1. A method for smooth-rolling and deep-rolling a plurality of pins, of a
crankshaft, comprising the following steps:
a) dividing said plurality of pins to be rolled into at least two groups of
pins,
b) including in each said group non-neighboring pins so that pins of one
group are spaced by pins of the other group and vice versa,
c) rolling all of the pins of one group simultaneously in one rolling
operation; and
d) rolling successive groups of pins in successive rolling operations.
2. The method of claim 1, comprising a further step of dividing said pins
into at least one further group of at least one pin, whereby each pin in
said further group is a main bearing pin, and rolling all pins of at least
one of said further group of pins together with one of the aforementioned
two groups of pins.
3. The method of claim 1, wherein a first group of main bearing pins is
included in one group of pins including crank pins, and wherein another
group of main bearing pins is included in another group of pins including
crank pins.
4. The method of claim 1, further comprising moving rolling means from one
rolling position into a successive rolling position after each successive
rolling operation.
5. An apparatus for smooth-rolling and deep-rolling of a plurality of pins
of a crankshaft, comprising frame means, means for rotatably holding said
crankshaft, means for rotationally driving said crankshaft about a
rotation axis, means for simultaneously rolling a group of non-neighboring
pins, crosswise carriage means for pendulously carrying said rolling means
and for moving said rolling means in a direction substantially radially to
said rotation axis, means for axially moving said rolling means in a
direction parallel to said rotation axis, means for fixing an axial
working position of said rolling means in any one of a plurality of
working positions, and a spacing between neighboring rolling means in an
axial direction, said spacing being sufficient for a pin of one pin group
presently not being rolled to be positioned between two neighboring
rolling means when said neighboring rolling means are rolling another
group of pins.
6. The apparatus of claim 5, wherein said pins include crank pins of said
crankshaft and wherein said means for simultaneously rolling a group of
non-neighboring pins comprise roller means for rolling at least said crank
pins.
7. The apparatus of claim 6, wherein said means for fixing an axial working
position comprise clamping means which are selectively operative on said
axial moving means.
8. The apparatus of claim 5, wherein said axial working position fixing
means comprise stop means.
9. The apparatus of claim 8, further comprising means for adjusting said
stop means into determined positions.
10. The apparatus of claim 5, wherein said means for axially moving said
rolling means comprise lengthwise carriage means which carry said
crosswise carriage means.
11. The apparatus of claim 10, wherein said axial moving means comprise
power-driven sliding means operatively connected to said lengthwise
carriage means.
12. The apparatus of claim 11, wherein said power-driven sliding means
comprise a pressure piston cylinder device comprising a dual-ended piston
rod.
13. The apparatus of claim 5, further comprising an axially slidable
support shaft, wherein said rolling means comprise respective rolling
tools, first mounting arms and second mounting arms, first journal means
articulately hinging a respective first arm and second arm to each other,
second journal means for articulately connecting said first arms to said
crosswise carriage means, and third journal means articulately connecting
said second arms to said axially slideable support shaft.
14. The apparatus of claim 13, further comprising common power-driven
sliding means, said axially slideable support shaft and said axial moving
means being operatively connected to said common power driven sliding
means.
15. The apparatus of claim 14, wherein said power-driven sliding means
comprise a pressure piston cylinder device having a dual-ended piston rod,
cylinder bracket means for holding said piston cylinder device in an
axially fixed manner, first and second bellcrank means each comprising
pivot point means for mounting the respective bellcrank means, and first
and second lever arms rigidly interconnected near said pivot point means,
wherein said first arm of said first bellcrank means is articulately
connected to said axially moving means, said first arm of said second
bellcrank means is articulately connected to said support shaft, and said
second arms of said first and second bellcrank means are each articulately
connected with respective opposite ends of said dual-ended piston rod.
16. The apparatus of claim 5, wherein said rotational driving means
comprise a drive motor for rotating said crankshaft and brake means for
precisely stopping the rotation of said motor, rotational angle sensor
means for sensing a respective rotational orientation of said crankshaft,
and machine control means for monitoring a sensed rotational orientation
of said crankshaft and for providing control signals to said motor and to
said brake means for rotating and stopping said work piece in at least one
prescribed rotational orientation.
17. The apparatus of claim 5, wherein said rolling means comprise a
plurality of rolling devices, and means for mounting at least one rolling
device of said rolling devices for movement in a crosswise direction
substantially perpendicular to said rotation axis independently of other
rolling devices.
Description
FIELD OF THE INVENTION
The invention relates to a method of smooth-rolling and deep-rolling a
workpiece., the crank pins of multi-crank or multi-stroke crankshafts. The
invention also relates to an apparatus for carrying out the present
method.
BACKGROUND INFORMATION
Methods of smooth-rolling and deep-rolling the bearing pins of multi-crank
or multi-stroke crankshafts are generally known. In this context the
deep-rolling operation is frequently limited to the area of the transition
radius or gusset between the bearing pin and the crank web or cheek. It is
a predominant goal in this field to simultaneously roll all of the bearing
pins, including the main bearing pins and all of the connecting rod crank
pins. Such a method is most economical as long as large numbers of the
same type of crankshafts are being manufactured. The economy is achieved
because the crankshaft is completely machined in a single work operation.
The original machines built to achieve this goal were specific application
machines built for a single exactly defined crankshaft type having one
specified set of dimensions. Unfortunately, such machines and the methods
they employed were quite uneconomical when various different crankshaft
types, namely crankshafts having different dimensions, were to be produced
and rolled in low number production runs. In those cases it would be
necessary to build a separate rolling machine for each different
crankshaft type. European Patent Publication No. 0,167,659 discloses
adjustable crankshaft rolling machines which overcome the above described
problem, but which are not able to simultaneously roll all of the bearing
pins. However, these machines could easily be adjusted to various
crankshaft dimensions and would then be used to successively roll the
various bearing pins of each crankshaft. U.S. Pat. No. 4,290,238 discloses
a similar apparatus. However, these two machines are very slow and thus
uneconomical in machining the crankshafts.
In all of the above described prior art machines the bearing pin rolling
devices are arranged respectively next to each other in such a manner that
two directly neighboring bearing pins may be rolled simultaneously in one
rolling operation. However, this method and arrangement of the rolling
tools of the rolling devices is not possible for crankshafts with
extremely closely spaced connecting rod crank pins because there is not
sufficient space for arranging the rolling devices directly next to each
other. In such cases it is only possible to use a single rolling device to
individually roll each connecting rod crank pin respectively in
succession. The rolling process thereby becomes slow and uneconomical even
for a series production of a relatively small number production run.
OBJECTS OF THE INVENTION
In view of the above, it is the aim of the invention to achieve the
following objects singly or in combination: to provide a method for
smooth-rolling and deep-rolling crankshaft bearing pins quickly and
economically with a minimum number of rolling operations even when the
bearing pins are located extremely closely together;
to provide an apparatus for carrying out such a method, whereby the
apparatus must be capable of smooth-rolling and deep-rolling crankshafts
of different dimensions; and
to enable such an apparatus to fully automatically carry out a complete
rolling operation on a crankshaft.
SUMMARY OF THE INVENTION
The above objects have been achieved by a method for smooth-rolling and
roll-hardening or rather deep-rolling a crankshaft according to the
invention, wherein all of the connecting rod crank pins of a crankshaft
are divided i.e., into two group wherein first the crank pins of one group
are rolled and then the crank pins of the other group are rolled. Each
group includes alternating connecting rod crank pins, which are not
directly neighboring each other. In this manner only two rolling
operations must be carried out, even if a substantial number of individual
connecting rod crank pins are to be rolled. Because of the alternating
arrangement to form each group, sufficient room is provided for arranging
the rolling devices. Thus, the alternating arrangement of connecting rod
crank pins into two groups makes it possible to locate the rolling devices
next to each other and to roll all pins of the same group together or
simultaneously. Further it is possible during the rolling of one group of
connecting rod crank pins in a first operation, simultaneous to roll or
merely one group of the bearing pins as well, so that the additional
rolling of the main bearing pins does not require additional time or
additional working operations.
The apparatus according to the invention for performing the present method
is a crankshaft deep- and smooth-rolling machine, including a machine
frame and means for receiving and rotationally driving at least one
multi-throw or multi-stroke crankshaft about a rotational axis. The
apparatus further includes main bearing pin rolling devices carrying
rolling tools and at least two connecting rod crank pin rolling devices
carrying rolling tools which are suspended to operate as a pendulum in a
plane perpendicular to the rotational axis of the work piece, from a
carriage for a radial sliding adjustment and a radial positioning
adjustment. According to the invention the connecting rod crank pin
rolling devices are axially slideable together or in common between two
preadjusted or preadjustable positions in which they may be fixed or
locked. In this arrangement the connecting rod crank pin rolling devices
are spaced from one another in the adjustment sliding direction at such a
distance that at least one connecting rod crank pin fits into the space
between two neighboring connecting rod crank pin rolling devices in their
working position. With such an arrangement of the rolling devices, there
is sufficient space to arrange the connecting rod crank pin rolling
devices next to one another for at least one of the groups of crank pins
to be rolled. After completing a first rolling operation on a first group
of connecting rod crank pins, a simple sliding adjustment of the rolling
device arrangement allows the second group of connecting rod crank pins to
be rolled, thereby completing the entire rolling process. Simple carriages
may be used to permit the sliding adjustment of the rolling device
arrangement in which the rolling devices assume a rigid position relative
to one another at least during the sliding adjustment. Only two different
positions must be assumed by the adjustment carriage. Thus, these two
positions may be simply determined by appropriately arranging stops or
limit blocks. These stops may also be adjustably arranged. After the
carriage is driven into each respective working position, the carriage may
be held in the working position, for example, by a clamping mechanism or
by driving the carriage against the stop with the position adjustment
drive means. The sliding of the carriages into the two different working
positions may be power driven. The radial sliding adjustment of the
connecting rod crank pin rolling devices may be carried out individually
for each device or may be carried out simultaneously and in common for all
devices. In the first instance, a separate drive must be provided for each
individually adjustable device. In the second instance a single drive
suffices for all devices.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be clearly understood, it will now be
described, by way of example, with reference to the accompanying drawings,
wherein:
FIGS. 1, 1A are front schematic views of an apparatus according to the
invention for smooth-rolling and deep-rolling a crankshaft;
FIG. 2 is a cross-section along the line II--II in FIG. 1A;
FIG. 3 is a simplified or stylized three-dimensional perspective view of a
crankshaft to be operated on in the apparatus shown in FIGS. 1, 1A; and
FIG. 4 is a view partially in section taken along line IV--IV of FIG. 1A,
on an enlarged scale compared to FIG. 1.
DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND OF THE BEST MODE
OF THE INVENTION
As shown in FIGS. 1, and 1A a crankshaft 1 is mounted and at one end by
means of a chuck 2 and at the other end by a dead-center point 3, whereby
the crankshaft can be rotationally driven in a machine frame 83. A drive
motor 4 drives the chuck 2 and thus the crankshaft 1 which rotates about
its rotational axis 5. The crankshaft 1 includes main bearing pins 6, 7,
8, and 9. Main bearing pin rolling devices 10, 11, 12, and 13 rest with
their rolling tools which are not shown in detail in FIGS. 1 and 1A
against the main bearing pins 6, 7, 8, and 9 respectively. The
construction and operation of such rolling tools are known in the art and
therefore require no further description. The main bearing pin rolling
devices 10, 11, 12, and 13 are arranged to extend with their main
extension direction essentially vertically. The main bearing pin rolling
devices 10, 11, 12, and 13 are movably received at their lower ends in
bearing brackets 14, 15, 16, and 17, comprising spring bearings of which
only the spring bearing 87 of the bearing bracket 17 is shown. Each of the
upper ends of the main bearing rolling devices 10, 11, 12, and 13 is
similarly movably mounted in a spring bearing of which only the upper
spring bearing 56 receiving the main bearing rolling device 13 is shown.
The rolling devices 10, 11, 12, and 13 are movably held in this manner to
compensate any tolerance variations.
The crankshaft 1 comprises a first group of connecting rod crank pins 18,
19, and 20 which are contacted by the crank pin rolling devices 21, 22,
and 23 respectively. Each pin rolling device comprises an upper arm 27,
28, and 29 respectively and a lower arm 34, 35, and 36 respectively. The
crank shaft 1 comprises a second group of connecting rod crank pins 24,
25, and 26 which are not contacted by rolling devices during the operation
shown in FIGS. 1 nd 1A. The crank pin rolling devices 21, 22, and 23 are
arranged with their main extension directed essentially horizontally so
that the crank pin rolling devices 21 22, and 23 are arranged at an angle
relative to the main bearing pin rolling devices 10, 11 and 12, 13 while
forming respective planes extending perpendicularly to the rotation axis 5
of the crankshaft 1. In this manner it is achieved that the main bearing
pin rolling devices 10, 11, 12, and 13 and the crank pin rolling devices
21, 22, and 23 may be arranged close together with little space between
adjacent rolling devices.
As further shown in FIG. 1A and in a side view in FIG. 2, upper or first
arms 27, 28, and 29 of the crank pin rolling devices 21, 22, and 23 are
hingeably mounted by levers 30, 31, and 32 which pivot or journal the
crank pin rolling devices 21, 22, by a lengthwise carriage 44. The lower
or second arms 34, 35, and 36 of the crank pin rolling devices 21, 22, and
23 are connected by means of articulated support means 37, 38, and 39,
respectively to a support shaft 40 which is mounted in an axially movable
manner in bearing blocks 41 and 42 as shown especially in FIG. 1A.
The support shaft 40 and the lengthwise carriage 44 are synchronously
driven in the direction of arrow 43 shown in FIG. 1A parallel to the
rotation axis 5 by means of a pressure cylinder 45 comprising dual piston
rods 84 and 84'. The pressure cylinder 45 is pivotally, but nonslideably
held in forks 60 and drives the support shaft 40 and the lengthwise
carriage 44 through the piston rods 84 and 84' and through angled
bellcrank levers 46 and 47 attached to respective outward ends of the
piston rods 84 and 84'. At their other free ends, the bellcrank levers 46
and 47 engage crank sliders 48 and 49 attached to the lengthwise carriage
44 and to the support shaft 40, respectively. Each bellcrank lever 46 and
47 is pivotally supported in a location fixed manner at a respective pivot
point 85 and 86 near the area of the elbow bend of each lever.
Other drive arrangements could be used to provide a synchronous sliding
drive of the carriage 44 and the support shaft 40. For example, the
pressure cylinder 45 comprising dual piston rods could be replaced by an
electric motor driving an axially fixed, but rotational threaded nut on a
threaded shaft or spindle, whereby the threaded shaft would then be driven
axially to perform the same function as the dual piston rods 84, 84' in
the depicted embodiment. As another alternative drive arrangement,
individual drives could be provided for the carriage 44 and the support
shaft 40, whereby the individual drives would be controlled to operate in
synchronism.
As shown especially in FIG. 2, the crosswise carriage 33 carrying the upper
arms 27, 28, 29 of each respective crank pin rolling device 21, 22, and 23
through the levers 30, 31, and 32, is driven in the direction 54
perpendicular to the rotation axis 5 by means of the pressure cylinder 50
which is attached at one end to the lengthwise carriage 44 and to the
crosswise carriage 33 by its piston rod 53. As an alternative to this
single combined drive for all crank pin rolling devices, a separate
individual drive could be provided for each rolling device so that each
individual rolling device could be slideably driven independently of the
other devices and at different times. Individual drives could be driven in
synchronism, if desired.
The extent of the lengthwise motion of the lengthwise carriage 44 in the
direction of arrow 43 shown in FIG. 1A and thus the axial position of the
crank pin rolling devices is determined by the stops 51 and 51'.
Simultaneously, the lengthwise motion of support shaft 40 is limited by
stops 52 and 52'. The extent of the crosswise motion of cross carriage 33
in the direction of arrow 54 as shown in FIG. 2 and thus the position of
the crank pin rolling devices perpendicular to the rotational axis 5 is
limited or determined by stops 55 and 55'.
FIG. 3 shows a simplified schematic illustration of a crankshaft 1 seen
from the left front side of FIG. 1A with the crankshaft 1 supported at one
end in the chuck 2 and at the other end on the dead-center point 3. The
crankshaft 1 comprises main bearing pins 6, 7, 8, and 9, a first group of
connecting rod crank pins 18, 19, and 20, and a second group of connecting
rod crank pins 24, 25, and 26.
In a first rolling operation of the crankshaft 1 the appropriate
corresponding rolling devices are brought into contact with all of the
main bearing pins 6, 7, 8, and 9, and with the first group of crank pins
18, 19, and 20. Each of the crank pins 18, 19, and 20 is spaced around the
circumference of the crankshaft 1 by an angle of 120.degree. from the
other first group of crank pins 18, 19, and 20, but are displaced by
60.degree. from the neighboring crank pins of the second group of crank
pins 24, 25, and 26, so that each crank pin is spaced by 60.degree. from
its neighboring crank pin.
The crank pin rolling devices 21, 22, and 23 comprising essentially known
rolling tools which are not shown in detail, are supported in such a
manner that during rolling the connecting rod crank pins 18, 19, and 20
and then the crank pins 24, 25, and 26, and the rolling tools can follow
the path of the respective connecting rod crank pin on a circular path 63
about rotation axis 5 as the crankshaft 1 is rotated.
In loading a crankshaft 1 into, or unloading a crankshaft 1 from, the
rolling apparatus according to the invention, the crankshaft 1 is always
in the same defined position, so that the crank pins 18, 19, and 20 are
also in respective defined positions at the time of loading and unloading.
The crank pin rolling devices 21, 22, and 23 are aligned to be in a
position in accordance with the defined position of the crank pins 18, 19,
and 20. For this reason it is necessary to rotate the crankshaft 1 into a
proper position determined by the alignment of the rolling devices in
order to start the second rolling operation during which the connecting
rod crank pins 24, 25, and 26 are to be rolled. Stated differently, the
crankshaft 1 is rotated so that the connecting rod crank pins 24, 25, and
26 take up the rotational positions originally occupied by the connecting
rod crank pins 18, 19, and 20. More specifically, the crank pin 24 is
moved into the initial rotational position of crank pin 18, crank pin 25
is moved into the initial rotational position of crank pin 19, and crank
pin 26 is moved into the initial rotational position of crank pin 20. For
this purpose a cam disk 62 is arranged on a shaft 61 between a drive motor
4 and the chuck 2 to facilitate the repositioning rotation of the
crankshaft 1 between the two rolling operations. The cam disk 62 is fixed
to the shaft 61 to rotate with the shaft 61. As shown especially in FIG.
4, the cam disk 62 is equipped with a cam 64 cooperating with a limit
switch 65 which defines the initial position of the chuck 2 and thus of
the crankshaft 1 during loading and unloading and at the beginning of the
first rolling operation. A further limit switch 66 shown in FIG. 4 defines
a second rotational position of the crank shaft 1. The limit switch 66 is
arranged on the circumference of the cam disk 62 in such a way that the
switch 66 can be operated by a cam 64. During the course of a work
sequence, the limit switches 65 and 66 are activated by the machine
control 67 as required. The control 67 may be a CNC control, for example.
The drive motor 4 which drives or rotates the chuck 2, and the limit
switches 65 and 66 are connected respectively by electrical conductors 68,
69, and 70 to the machine control 67 as shown in FIG. 4 and FIGS. 1 and
1A.
As an alternative to the cam disk 62 with its cam 64 and the limit switches
65 and 66, an angle transducer may be used for monitoring and controlling
the angular position of the crankshaft 1.
As shown in FIG. 2, the rolling force of the main bearing pin rolling
device 13 and its opening and closing motion are applied by means of the
rolling force cylinder 71. The remaining main bearing rolling devices 10,
11, and 12 shown in FIG. 1A are connected to similar rolling force
cylinders, not shown. Referring again to FIG. 2, the rolling force and the
force for the opening and closing motions of the crank pin rolling device
23 are applied by means of a rolling force cylinder 72. The crank pin
rolling devices 21 and 22 shown in FIG. 1 are each connected to similar
rolling force cylinders not shown since showing one such device at 72 is
sufficient.
When the crank pin rolling devices 21, 22, and 23 are rolling the
connecting rod crank pins, these crank pin rolling devices must be carried
along by the rotating motion of the respective crank pins as the
crankshaft 1 rotates. To enable such a circular motion of the crank pin
rolling devices 21, 22, and 23, these devices are suspended to be freely
movable in a plane perpendicular to the rotation axis 5. While inserting
or removing a crankshaft from the rolling apparatus and also while
shifting the crank pin rolling devices 21, 22, and 23 from a first rolling
position engaging crank pins 18, 19, and 20, to a second rolling position
engaging crank pins 24, 25, and 26, it is necessary that the crank pin
rolling devices 21, 22, and 23 are fixed in a basic initial position. FIG.
2 shows the crank pin rolling device 23 fixed in such an initial position,
wherein the crank pin rolling device 23 is fixed by means of the lever 73
which is pivoted in the direction 79 about the journal point, or rather
axis 75, by means of the pressure piston cylinder device 74. The lever 73
supports the crank pin rolling device 23 against cam 76 and simultaneously
thereby pivots lever 77 about the journal point or axis 78 to become
engaged with the strut 80.
While in this fixed position the crank pin rolling device 23 may also be
opened and closed by means of the rolling force cylinder 72. The crank pin
rolling devices 21 and 22, which are not shown in FIG. 2, are opened and
closed in the same manner. In order to release this fixed position, the
piston cylinder device 74 is supplied with pressure medium in such a
manner that lever 73 is driven in a direction opposite to that of arrow
79, whereby cam 76 is released and simultaneously lever 77 is separated
from the strut 80. However, this fixed position may only be released when
the respective crank pin rolling device is brought into full contact with
its respective bearing pin surface of the crankshaft 1.
A typical rolling operation on a crankshaft is carried out follows. At the
start, as shown in FIG. 1A, the crank pin rolling devices 21, 22, and 23
are located in a right-most lengthwise position, the lengthwise carriage
44 contacts the right stop block 51', and the stop 52 of the support shaft
40 rests against the bearing block 41. The lengthwise carriage 44 is held
in this position by the clamping means 82 and 82'. Also, as shown by
dash-dotted lines in FIG. 2, the crosswise carriage 33 is driven toward
the right in FIG. 2 away from the rotation axis 5 and rests against the
stop 55' while the crank pin rolling devices 21, 22, and 23 have been
fixed in the above described initial position by operating the pressure
cylinder 74 and the other pressure cylinders not shown in FIG. 2. Thus, as
shown in the example in FIG. 1A, with a sixth-crank crankshaft 1 the crank
pin rolling devices 21 and 22 are arranged to contact the crank pins 18
and 19 lying above the rotation axis and the crank pin rolling device 23
is arranged to contact the crank pin 20 located below the rotation axis in
this initial position. For this purpose the crank pin rolling device 23 is
suspended at a correspondingly lower level than the two other crank pin
rolling devices 21 and 22 as shown, for example, in FIG. 1A. Due to this
arrangement the crank pin rolling devices may be held to extend in an
essentially horizontal position as shown in FIG. 2, and may simply be
shifted back and forth in the direction of arrow 54 substantially radially
toward and away from the crankshaft 1, without requiring any pivoting or
tilting motion in order to move from the contact position shown in FIG. 2
to the release or removal position shown by dash-dotted lines in FIG. 2.
At the start, the main bearing rolling devices 10, 11, 12, and 13 and the
crank pin rolling devices 21, 22, and 23 are open at their rolling tool
end 81 and the rotation axis 5 is completely free and clear. The cam disk
62 on the shaft 61 is positioned by the drive motor 4 so that the cam 64
operates the now actuated limit switch 65, whereby the defined loading
position of the machine is established. A crankshaft 1 is inserted into
the rolling apparatus according to the invention by a loading apparatus
not shown, which places the crankshaft into the position shown in FIG. 1A
so that the crankshaft 1 is received between the chuck 2 and the
dead-center point 3. Next, the cross-carriage 33 is driven by the pressure
piston cylinder device 50 against the stop 55 so that the crank pin
rolling devices 21, 22, and 23 move with their rolling tools into the
working position. The rolling tools of the main bearing rolling devices
and the crank pin rolling devices are then moved with a slight force into
contact with the main bearing pins 6, 7, 8, and 9 and with the connecting
rod crank pins 18, 19, and 20, respectively. Simultaneously, the fixed
position of the crank pin rolling devices is released as described above
so that all the crank pin rolling devices are freely movable and so that
they may be freely entrained for rotation about the main axis 5 as the
crankshaft 1 rotates. Simultaneously, the drive motor 4 drives the chuck 2
to rotate the crankshaft 1 about the rotation axis 5. While the crankshaft
1 is rotating, the machine control 67 counts a predetermined number of
revolutions of the crankshaft during which the contact force of the
rolling devices is increased to the required rolling force for the
specific rolling operation being carried out by means of respectively
controlling the pressure piston cylinder devices 71 and 72 and the other
pressure cylinders which are not shown, but which function in the same way
as the piston cylinder devices 71, 72.
After a predetermined number of crankshaft revolutions during which the
full rolling force has been applied to the rotating crankshaft, the
rolling force is reduced at all rolling devices to the minimum contact
force while the crankshaft is still rotating. Then, the rotation of the
crankshaft 1 is stopped by stopping the drive motor 4 when the crankshaft
1 is again in its initial loading position. This loading position is
achieved upon stopping the rotation in that the cam 64 activates the limit
switch 65 which has been activated to control the shutting off of the
drive motor 4 and the application of a brake 4'.
Thus, after the completion of the first rolling operation, the crankshaft 1
has been rolled on all of the main bearing pins and three of the crank
pins making up the first group of crank pins 18, 19, and 20. The second
group of crank pins 24, 25, and 26 must be rolled in a second rolling
operation. For this purpose, the crank pin rolling devices 21, 22, and 23
are now fixed in their positions as described above by means of the
pressure piston cylinder device 74 and respective other pressure cylinders
not shown. The respective upper arms 27, 28, and 29 and lower arms 34, 35,
and 36 of the rolling devices 21, 22, and 23 are opened at the tool end 81
by means of the rolling force piston cylinder device 72, and by the other
rolling force cylinders 72' and by one further cylinder not shown. Then,
the cross-carriage 33 is pulled against the stop 55' by means of the
pressure piston cylinder device 50. In this manner, the crank pin rolling
devices 21, 22, and 23 have released and freed the crankshaft 1. Then, the
clamping device 82, 82' of the lengthwise carriage 44 is released and the
pressure cylinder 45 is actuated to drive the lengthwise carriage 44 and
the support shaft 40 by the bell crank levers 46, 47 in the direction of
arrow 43 against the stop 51, whereby stop 52' moves against the bearing
bracket 41. Then, the clamping device 82 and 82' is again activated. Now,
the crank pin rolling devices 21, 22 and 23 are located in a cross or
alignment plane with the second group of crank pins 24, 25 and 26. The
crankshaft 1 must be rotated so that the crank pins 24, 25, and 26 move
into the above described angular positions corresponding to the angular
position of the first group of crank pins 18, 19, and 20 and corresponding
to the relative positions of the crank pin rolling devices 21, 22, and 23.
For this purpose, the limit switch 66 is activated and the drive motor 4
is switched on by the machine control 67. As the cam disk 63 rotates the
cam 64 contacts the limit switch 66 which shuts off the drive motor 4 and
activates the brake 4'. Now, the crankshaft 1 is positioned in the
necessary rotational or angular position. Then, the pressure cylinder 50
is activated to drive the cross-carriage 33 to the left in FIG. 2 against
the stop 55 so as to move the crank pin rolling devices 21, 22, and 23
into position for carrying out the second rolling operation. The rolling
force cylinders 72 close the tool end 81 of the crank pin rolling devices
21, 22, and 23 so that the respective rolling tools contact the crank pins
24, 25, and 26 with a minimum contact pressure. The main bearing pin
rolling devices 10, 11, 12, and 13 are not brought into contact with the
main bearing pins 6, 7, 8, and 9 in this second rolling operation because
the main bearing pins have been completely machined during the first
rolling operation. However, it would also be possible to carry out only a
partial rolling of the main bearing pins during the first rolling
operation and complete the necessary rolling during a second rolling
operation. As soon as the respective crank pin rolling devices come into
contact with the crank pins, the position fixing of the crank pin rolling
devices is released as described above and drive motor 4 is activated to
rotate the crankshaft 1 about the rotation axis 5. While the crankshaft 1
rotates, the rolling force is increased from the initial low contact force
to the required full rolling force during a certain number of revolutions
of the crankshaft 1 by appropriately activating the rolling force
cylinders 72. After carrying out a prescribed number of crankshaft
revolutions while applying the full rolling force, the rolling force is
then again reduced to the minimum contact force while the crankshaft 1
continues to rotate through a predetermined number of revolutions. Then,
the crankshaft 1 is stopped when it is in a proper rotational position
corresponding to the starting position of the second rolling operation
through the action of the cam 64 contacting the limit switch 66 which has
been activated so that is now provides the signal for shutting off the
drive motor 4 and applying the brake 4'. The crank pin rolling devices 21,
22, and 23 are again fixed in their position as described above and the
tool ends 81 of the rolling devices are again opened as described above.
Simultaneously, the main bearing rolling devices 10, 11, 12, and 13 are
opened. The cross-carriage 33 is pulled by the pressure piston cylinder
device 50 against the stop 55' in order to withdraw the crank bearing
rolling devices 21, 22, and 23 away from the crankshaft 1. Now, the
crankshaft 1 is again rotated into the initial loading and unloading
rotational or angular position by means of the drive motor 4 controlled by
the action of cam 64 cooperating with limit switch 65. A loading and
unloading apparatus, which is not shown, can then remove the completely
machined or rolled crankshaft 1 and load a new crankshaft to be rolled.
Before a new rolling operation begins on the new crankshaft the crank pin
rolling devices 21, 22, and 23 must be driven back into the initial
lengthwise position shown in FIG. 1A by the appropriate activation of the
pressure piston cylinder device 45.
Although the invention has been described with reference to specific
example embodiments, it will be appreciated, that it is intended to cover
all modifications and equivalents within the scope of the appended claims.
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